1. Field of the Invention
The present invention relates to a broadcasting/communication system that uses a linear code based on a parity check matrix.
2. Description of the Related Art
Shortening or puncturing may be applied to a parity check code in a broadcasting/communication system in order to obtain various code lengths or performance improvements.
When a transmission terminal shortens a portion of an information word, a limitation of a value ‘0’ is set to a predetermined position. Because a receiver knows this already, the transmission terminal does not transmit values limited to ‘0’.
Shortening may be performed by limiting a value of a portion of an information word bit to ‘0’, and may be performed by not using a column corresponding to an information word bit whose values are limited to ‘0’ in a given parity check matrix.
When applying puncturing to a given parity check code, a receiver regards punctured bits as erasures to perform decoding using a parity check matrix of the parity check code. However, this decoding method becomes more inefficient as the number of punctured bits increases.
More specifically, when a broadcasting/communication system that uses a Low Density Parity Check (LDPC) code applies iterative decoding, a slow decoding convergence characteristic is represented, thereby limiting performance improvement within a limited decoding complexity.